Standpipe vent system and fitting for multi-story buildings

ABSTRACT

An improved sanitary drain system for multi-story buildings is disclosed. A loop vent fitting is provided in the waste or soil stack at each floor where the horizontal branch line connects with the soil stack. This facilitates the venting of each fixture in the system without the use of a separate vent stack running parallel to the soil stack. The loop vent fitting comprises a loop shaped pipe with openings at top and bottom for connection into the soil stack, and two openings on one side of the loop. The upper side opening is for connection to the vent system of the subjacent floor and the lower side opening is for connection to the branch line of the floor adjacent the loop vent fitting. In this way, each fixture is in venting communication with the roof vent via the loop vent fittings, horizontal branches and vent pipes of all floors above.

United States Patent 91 Dumas [4 1 Nov. 19, 1974 STANDPIPE VENT SYSTEM AND FITTING I Primary Examiner-John W. Huckert FOR MULTl-STORY BUILDINGS Assistant Examiner-{on W. Henry [76] Inventor: Emile V. Dumas, 307 Washington Attorney Agent or Flrm 0wen Owen St., Monroe, Mich. 48161 [5 ABSTRACT [22] Wed: July 1973 An improved sanitary drain system for multi-story [21] Appl. No.: 381,494 buildings is disclosed. A loop vent fitting is provided in the waste or soil stack at each floor where the horizontal branch line connects with the soil stack. This CClI. 4/2l1l30l3ZL7/93/3Z facilitates he venting each fixture in the System 58] Fie'ld I357 without the use of a separate vent stack running paral- 285/153 lel to the soil stack. The loop vent fitting comprises a loop shaped pipe with openings at top and bottom for [56] References Cited connection into the soil stack, and two openings on one side of the loop. The upper side opening is for UMTED A E PATENTS connection to the vent system of the subjacent floor 1,523,946 1/1925 Fruin 4/211 and the lower side opening is for connection to the FOREIGN PATENTS OR APPLICATIONS branch line of the floor adjacent the loop vent fitting. 2 1,1939 0 t B in M2 in this way, each fixture 1s m venting communication 4985 8 n a with the roof vent via the loop vent fittings, horizontal branches and vent pipes of all floors above.

8 Claims, 6 Drawing Figures g \e l 5 2B 25 2oz 25 26 3226 25 A El 35 Q- 2 l 14/ /l 25 2&1 l 20 204 T: r -11 'jj Q":

z asi STANDPIPE VENT SYSTEM AND FITTING FOR MULTI-STORY BUILDINGS BACKGROUND OF THE INVENTION This invention relates to sanitary systems and particularly to an improved sanitary waste system and fitting for multi-story buildings.

Sanitary drainage systems for multiple story buildings comprise essentially a vertical stack of soil pipes, open to the atmosphere at the roof, through which liquid and solid wastes fall to a sewer pipe below. The sewer pipe generally runs laterally with only a gentle slope, conducting the wastes to the public sanitary sewer system. Lateral or horizontal drain pipes, also of gentle slope, tie into the vertical soil stack at each floor generally be means of simple T or Y fittings. Fixtures such as toilets, sinks, wash basins and baths are connected through traps to the lateral drain pipes. The trap associated with each fitting is generally a simple U-tube which is intended to be kept filled with water to prevent foul sewer gases from escaping through the fixture drain to the interior of the building.

In operation, these systems present a problem. When a large volume of water and waste is discharged into the system in a short time, as by flushing one or several toilets, negative pressures may be created within the system at the floor where the discharge occurs and at lower floors. The negative pressures are often of sufficient magnitude to cause siphoning of the water out of the traps of the fixtures on the affected floors. Similarly, excessive positive pressures are often simultaneously created at floors near the base of the stack, blowing the water out of the traps. The effect is that objectionable and even hazardous amounts of sewer gas v may escape into the affected area.

, Generally the condition chiefly responsible for the negative pressures is the blocking of the drain stack by water and waste when it flows into the stack from the lateral floor drain pipe. Falling water below this point of blockage tends to create a negative or decreased pressure for a few floors below the blockage and a positive or increased pressure below the falling water itself.

This problem may be solved by greatly oversizing the vertical soil stack, but this involves unnecessary expense. The most common solution, also very expensive but required by many building codes, is to parallel the soil drain stack with a separate vent stack, to which is connected through revent pipes either the trap of each fixture or the lateral floor drain pipe near each trap. This provides an escape for positive or negative pressures, so that they do not blow or siphon the fixture traps and allow sewer gases to escape into the building. Other methods of venting have been suggested, such as that of US. Pat. No. 3,346,887, but have not been widely accepted by building codes and are seldom found in practice.

SUMMARY OF THE INVENTION The present invention provides a sanitary system for multi-story buildings which eliminates the costly separate vent stack and utilizes a single conventionallysized soil drain stack. Each floor branch line of the system has an upper revent portion, as is customary, which leads back toward the soil stack above the point of connection between the stack and the downstream discharge end of a floor branch line. But instead of being connected directly into the soil stack or to a separate vent stack, the revent portion ties into a loop vent fitting of the present invention. The discharge end of the floor branch line above is also connected to this loop vent fitting. At the uppermost floor, the revent portion ties directly into a vent which is an extension of the soil stack and is always directly open to the atmosphere. In this way the system connects all floor branch lines in series to serve as a vent pipe, and each fixture is vented through the branch lines above as if it were connected directly to the vented soil stack above the highest fixture.

The loop vent fitting which facilitates this improved, inexpensive venting method is essentially a vertically bifurcated pipe with four openings: one at each of the top and the bottom of the fitting where the bifurcations join for connecting the fitting in series in the soil stack and two on a first of the bifurcations. Of these latter two openings, the lower is connected to the discharge end of the horizontal branch line of the adjacent floor, and the upper is connected to the revent portion of the branch drain line of the floor below. The waste from the horizontal branch line is thus prevented from entering the revent of the floor below. Similarly, at the top of the loop vent fitting, the first bifurcation branches from the second at a right angle or a slightly upward slope, so that sewage descending through the soil stack will flow only through the second bifurcation.

The second bifurcation is preferably slightly bowed or curved for slowing the rate of descent of the waste. This is usually desirable in a sanitary system to minimize the rate at which air rushes through the system and to reduce the splashing and noise produced by the falling waste.

It is apparent that the system of this invention depends upon less than full flow in its lateral or horizontal branch lines, since these lines must pass air to vent all lower fixtures. Thus the horizontal branch lines must be sized and the fixtures spaced along each line so that the line never flows full under any use conditions. Most building codes presently specify pipe sizing and fixture density that will satisfy this requirement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic elevational view of a prior art sanitary drainage system in a multi-story building including a separate vent stack according to present common practice and many building codes;

FIG. 2 is a diagrammatic elevational view of a multistory building with a sanitary drainage system according to the present invention;

FIG. 3 is an elevational view of a loop vent fitting according to the present invention;

FIG. 4 is a cross-sectional view taken along line-4-4 of FIG. 3;

FIG. 5 is an end view of the fitting shown in FIG. 3; and

FIG. 6 is a diagrammatic elevational view of a modified drainage system embodying the-'invention, in a multi-story building having fixtures over alarge floor area.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning to FIG. 1, a typical prior art sanitary drainage system in a multi-story building is illustrated. The

system includes a vent stack separate from a soil stack 11. Revent pipes 12 from various lines and fixtures enter the vent stack 10 above the point where their corresponding horizontal branch lines 13 enter the soil stack 11. A roof vent 14 keeps the soil stack 11 and vent stack 10 open to the atmosphere. The soil stack 11 is connected below the bottom floor to a lateral sewer pipe 15 leading to the public sanitary sewer (not shown).

A sanitary drainage system for multi-story buildings, according to the present invention, is shown in FIG. 2 and is generally indicated by the reference number 16. The system 16 includes a roof vent 17, a soil stack 18, a lateral sewage line 19, one or more floor branch drain circuits 20 each including a lateral or horizontal branch line 21 and a revent 22, and loop vent fittings 23 and 24. Various sanitary fixtures such as toilets 26, wash basins 27 and baths 28 are'connected through fixture branches to discharge their wastes through the horizontal branch lines 21, the downstream loop vent fittings 23 and 24, the soil stack 18 and the lateral sewer pipe 19 into the public sanitary sewer (not shown). Auxiliary revent pipes 29 may be included in any floor branch drain circuit 20, depending upon the density and type of fixtures on each branch line 21 and the requirements of local building codes.

The improved system 16 eliminates the need for a separate vent stack such as the vent stack 10 of FIG. 1 by providing a continuing atmospheric communication through the branch sanitary drain circuits 20 and the loop vent fittings 23 from the roof vent 17 to the lowest loop vent fitting 24. Thus, each fixture is properly vented to the exterior atmosphere at all times.

It is significant that in a building sanitary system such as this, the fixture branches 25 often flow full, but the horizontal branch lines 21 are generally sized so that they never flow full. Therefore, air can be forced down one or more of the relatively short fixture branches 25 and into the horizontal branch line 21, but it will always find space to escape through the branch line 21 and one or both of the revents 22 and 29 to the upper loop vent fittings 23 of the floor branch circuit 20, and finally through the roof vent 17. Similarly, positive and negative pressures that might otherwise develop in the soil stack 18 and consequently in the horizontal branches 21 are vented to the atmosphere and cannot blow or siphon traps in the fixture branches 25.

The loop vent fitting 23 is shown in detail in FIGS. 3, 4 and 5. It preferably comprises a vertically bifurcated pipe having top and bottom openings 30 and 31, respectively, adapted for connection in series with the soil stack 18. Upper and lower spaced openings 32 and 33, respectively, are provided on a first side 34 of the loop vent fitting 23. The upper opening 32 is preferably connected to the revent 22 of the branch drain circuit 20 for the floor immediately below the fitting. The

, lower opening 33 is connected to receive discharge from the horizontal branch 21 of the adjacent floor. This arrangement prevents sewage from the horizontal branch 21 from entering the lower revent 22 and facilitates the free passage of air between these pipes.

This first bifurcation or side 34 of the loop vent fitting 23 preferably branches perpendicularly from or at a slightly upward angle from a second side 35, so that sewage descending through the soil stack 18 is normally prevented from entering the first side 34. In addition, the second side 35 has an enlarged portion 36 just below the splitting of the two sides 34 and 35 for the same reason.

The second bifurcation 35 preferably includes a slightly curved portion 37 for slowing the rate of descent of the sewage down the stack 18. As shown in FIGS. 3 and 4, the curved portion 37 has an enlarged cross section so that stoppage willnot occur at this slowing point.

The lower horizontal branch opening 33 is connected to an area 38 of the first bifurcation 34 which preferably has an angle of about 45 to the vertical. A gentle curve 39 is provided at the connection so that sewage can flow freely from the opening 33 into the area 38 of the loop vent fitting without blockage. The area 38 also has an enlarged cross section to further prevent blockage.

The two sides 34 and 35 of the loop vent fitting 23 are rejoined at a lower junction 40. As indicated in FIG. 3, the angles of the sides from the vertical at this junction 40 are preferably quite steep. Also, gentle curves 41 and 42 are formed in the pipe walls. These characteristics tend to prevent blockage at this point and to keep the junction 40 partially filled with air. Thus, the soil stack 18 can usually act as an auxiliary venting means for the system 16.

In FIG. 2, the lowest loop vent fitting 24 is modified from the normal fitting 23 in that it has no upper opening to receive a revent from a floor below. It may comprise an entirely different fitting or simply a normal fitting 23 having a plug 43, as shown in FIG. 2. The fitting 24 is otherwise similar in structure to the other fitting 23.

FIG. 6 shows a modified building drainage system, according to the invention, which is generally indicated by the reference number44. The system 44 illustrates the usefulness of a loop venting system in a multi-story building with widely distributed fixtures. The fixtures 45 most distant from the soil stack 46 cannot be economically revented to the loop vent fittings 47 because of the large amount of revent piping that would be required. Therefore, a separate vent stack 48 is provided to vent the portion of the system 44 remote from the soil stack 46. Fixtures 49 closer to the soil stack 46 are vented by loop venting as in FIG. 2, which eliminates the need for a second vent stack such as the vent stack 10 of FIG. 1.

The above-described preferred embodiments provide an improved building sanitary drainage system and fitting therefor which eliminates the need for a separate vent stack paralleling the soil stack in multi-story buildings. The useof this relatively inexpensive fitting economizes on piping. Various other embodiments and alterations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the following claims.

What I claim is:

1. A sanitary system for a multi-story building, comprising, in combination, a plurality of sanitary fixtures with drains on different floors, a vertical drain stack having upper and lower ends and including a plurality of vertically oriented drain pipes and'a plurality of loop vent fittings connecting said drain pipes in series, one loop vent fitting adjacent each floor having a sanitary fixture, each loop vent fitting including a closed loop conduit with connecting means, a sanitary sewer pipe, means connecting said sewer pipe to the lower end of said drain stack, a roof vent, means connecting said roof vent to the upper end of said drain stack, at least one branch sanitary drain circuit for each floor having a fixture, each circuit having a soil end connected to said connecting means on the loop vent fitting for the adjacent floor and a venting end connected to said connecting means on the first superjacent loop vent fitting in the drain stack, means connecting said venting end of the uppermost branch circuit to the atmosphere, and means connecting the drains of all fixtures on each floor to the adjacent branch sanitary drain circuit intermediate said soil end and saidventing end.

2. A sanitary system according to claim 1, wherein each loop vent fitting comprises a generally closedcircuitloop shaped fitting having upper and lower ends, wherein said connecting means includes means for connecting said fitting in series with said vertical drain pipes, first opening means on one side of said fitting for connection to the soil end of a branch circuit for an adjacent floor and second opening means on said one side for connection to the venting end of any branch circuit of a subjacent floor, and means for preventing a flow of sewage between said first and second opening means.

3. A sanitary system according to claim 2, wherein said flow preventing means comprises said first opening means positioned below said second opening means on said one side to prevent a flow of sewage between said first and second opening means.

4. A sanitary system according to claim 1, wherein each loop vent fitting includes means for substantially preventing the flow of sewage from said vertical drain pipes into the soil end of a connected branch circuit, and means for substantially preventing the flow of sewage from said vertical drain pipes into the connected venting end of a branch circuit for a subjacent floor.

5. A sanitary system according to claim 1, wherein said loop vent fitting includes means for limiting the flow rate of sewage passing down said vertical drain stack.

6.A sanitary drain system for a multi-story building comprising, in combination, a substantially vertical soil stack having a roof vent at its upper end and having a lower end connected to a sanitary sewer pipe, at least one branch sanitary drain circuit for substantially every floor, each circuit including a sewage branch and at least one revent communicating therewith, said sewage branch having a downstream end, means connecting said downstream end of said sewage branch into said stack, at least one sanitary fixture connected to each sewage branch, means connecting each revent into said stack closely adjacent and above the downstream end of the immediate superjacent sewage branch, means for preventing the flow of sewage from said sewage branches to said revents, and means effecting communication between the revent of the uppermost floor and said roof vent.

7. The sanitary system of claim 6, and further including means effecting communication between each revent and said stack independent of said sewage branches, and means for preventing a flow of sewage from said stack into said revents.

8. A sanitary system according to claim 6, wherein said stack includes means at substantially every floor for limiting the flow rate of sewage passing down said vertical drain stack. 

1. A sanitary system for a multi-story building, comprising, in combination, a plurality of sanitary fixtures with drains on different floors, a vertical drain stack having upper and lower ends and including a plurality of vertically oriented drain pipes and a plurality of loop vent fittings connecting said drain pipes in series, one loop vent fitting adjacent each floor having a sanitary fixture, each loop vent fitting including a closed loop conduit with connecting means, a sanitary sewer pipe, means connecting said sewer pipe to the lower end of said drain stack, a roof vent, means connecting said roof vent to the upper end of said drain stack, at least one branch sanitary drain circuit for each floor having a fixture, each circuit having a soil end connected to said connecting means on the loop vent fitting for the adjacent floor and a venting end connected to said connecting means on the first superjacent loop vent fitting in the drain stack, means connecting said venting end of the uppermost branch circuit to the atmosphere, and means connecting the drains of all fixtures on each floor to the adjacent branch sanitary drain circuit intermediate said soil end and said venting end.
 2. A sanitary system according to claim 1, wherein each loop vent fitting comprises a generally closed-circuit loop shaped fitting having upper and lower ends, wherein said connecting means includes means for connecting said fitting in series with said vertical drain pipes, first opening means on one side of said fitting for connection to the soil end of a branch circuit for an adjacent floor and second opening means on said one side for connection to the venting end of any branch circuit of a subjacent floor, and means for preventing a flow of sewage between said first and second opening means.
 3. A sanitary system accOrding to claim 2, wherein said flow preventing means comprises said first opening means positioned below said second opening means on said one side to prevent a flow of sewage between said first and second opening means.
 4. A sanitary system according to claim 1, wherein each loop vent fitting includes means for substantially preventing the flow of sewage from said vertical drain pipes into the soil end of a connected branch circuit, and means for substantially preventing the flow of sewage from said vertical drain pipes into the connected venting end of a branch circuit for a subjacent floor.
 5. A sanitary system according to claim 1, wherein said loop vent fitting includes means for limiting the flow rate of sewage passing down said vertical drain stack.
 6. A sanitary drain system for a multi-story building comprising, in combination, a substantially vertical soil stack having a roof vent at its upper end and having a lower end connected to a sanitary sewer pipe, at least one branch sanitary drain circuit for substantially every floor, each circuit including a sewage branch and at least one revent communicating therewith, said sewage branch having a downstream end, means connecting said downstream end of said sewage branch into said stack, at least one sanitary fixture connected to each sewage branch, means connecting each revent into said stack closely adjacent and above the downstream end of the immediate superjacent sewage branch, means for preventing the flow of sewage from said sewage branches to said revents, and means effecting communication between the revent of the uppermost floor and said roof vent.
 7. The sanitary system of claim 6, and further including means effecting communication between each revent and said stack independent of said sewage branches, and means for preventing a flow of sewage from said stack into said revents.
 8. A sanitary system according to claim 6, wherein said stack includes means at substantially every floor for limiting the flow rate of sewage passing down said vertical drain stack. 